An air quality index (AQI) of 340 (very poor) was recorded at 9am on Thursday, compared to a 24-hour average of 336 (very poor) at 4pm a day earlier. The air quality was likely to remain “very poor” on Thursday and improve from Friday.

An AQI between 0 and 50 is classified as “good”, 51 and 100 “satisfactory”, 101 and 200 as “moderate”, 201 and 300 as “poor”, between 301 and 400 as “very poor”, and over 400 “severe”

An India Metrological Department (IMD) official said a fresh and more active western disturbance was expected to cause very light to light rain on Thursday evening. “The weather conditions might get more intense on Friday, when Delhi is likely to experience moderate rain and thunderstorms, accompanied by lightning and gusty winds of speed 30-40 kmph,” said the official.

The minimum temperature was likely to touch 11°C by Friday and then dip at the beginning of next week. The maximum temperature was also expected to decrease next week following the thundershowers. It was expected to be around 23°C on Thursday.

The IMD has issued a yellow alert until Sunday, warning people of thunderstorms and dense fog. A dense fog enveloped Safdarjung, which is representative of Delhi’s weather. IMD said the visibility at Safdarjung was 100m from 7.30am to 8am and 300m .at Palam at 8am even as no flight disruptions were reported.